A standard garden chopping/shredding apparatus has a frame carrying an upwardly open intake hopper having a lower end in which is a generally horizontal blade plate rotatable about an upright axis and formed about the axis with a plurality of angularly spaced apertures. Respective flat blades carried on the blade plate have cutting edges above the apertures and a plurality of prechopping blades are carried on the blade plate and project upward and outward therefrom. A drive can rotate the plate and he blades in a predetermined direction about the axis to define with the cutting edges of the flat blades a generally planar and circular orbit perpendicular to the axis and having an inner periphery offset radially outward from the axis and to define with the cutting edges of the chopping blades an orbit shaped as a body of revolution. A deflector or abutment plate fixed against rotation in the lower end of the hopper has a panel with a lower cutting edge juxtaposed with the orbit of the flat blades and another edge juxtaposed with the orbit of the prechopping blades.
As described in German Patent document 2,934,792 the prechopping blades are oriented in a V and the abutment plate is triangular and substantially vertical, that is parallel to the blade rotation axis. The lower side of the abutment plate acts as a counteredge for the flat blades and its outwardly inclined edges work with the inner edges of the prechopping blades. Branches of any size are fed into the device through a lateral feed tube that bypasses the abutment plate and that opens at its inner end directly above the flat blades and adjacent the prechopping blades.
Thus with this known device it is necessary to sort the material being chopped, feeding small twigs, leaves, and the like into the hopper and inserting the lager branches into the separate large-material tube. In addition this arrangement must rotate its blades at very high speed, often several thousand revolutions per minute, so that the machine makes a high-pitched and very annoying noise. Finally the known machines jam rather easily, require that the material be pushed into them, and their blades wear out rapidly.